Process for the manufacture of 2-mercapto-thiazoline



alcohol; or alcohol-water.

phase medium is to be distinguished from a two-' phase system such as carbon disulphide and water, in which the low boiling liquid carbon, disulphide layer would tend to limit-the tem- 'perature of reaction and thus bring about a long tion of Z-mercaptdthiazoline:

Patented Sept 7; 1943 I' Y UNITED STATES PAT a An object of this invention is to provide a new" process for the manufacture ,of '2 -mercapta thiazolines. Another object is to providesuch a a i process whichis economical to practice and yield ing' a highly commercial product.

According to the invention,a beta-amino alkyl for three hours. On cooling, 2-mercapto-thiazoline (melting point IDS-107 C.) crystallizes from *thesolution. The yield may be; slightly improved f by acidifying the filtrate with sulfuric acid sulphuric acid is reacted with an alkali alkylfl' xanthogenate, in the presenceof alkaliusing a.

liquid single phase medium, for example, water,,

The use of a single time reaction. In contrast, the presentfprocedure permits higher temperature and hence Q [more rapid reaction. The amount of alkali used ,i fsuch as sodium hydroxide is molecularly equivalent to the amount of the alkali alkyl xanthogenate used. In practice a small amount of acid is used to acidify the solution after therep action is completed, and where an excess of alkali :is originally used, a chemically equivalent amount 1 of :acid should be added to free the Z-mercaptotriazoline.

The following exampleillustrates the preparaa 13.0 grams (0.1 mollofsodium methyl xantho ,genate are dissolved in a mixture of 15grams of methyl alcohol and 4 grams of water. To this solution is added 14.1,grams(0.1 mo1) of betavolume and'cooling. I a

Instead of sodium methyl xanthogenate, other j (about cc. of 6-normal), evaporating to cc.

alkali methyl x anthogenates, or othersodium alkylxanthogenates, or other alkali methylalkyl xanthogenates, maybe used. i

The preferred temperatures of reactionare from TOP-100 C. although the invention is not limited to these temperatures. a I

Although agitation is not mentioned in the above example, it may be employed during the course of thereaction. The time of mixingof reactants may be slow or rapid.

Also the method of theinvention is not limited to method of heating, type of reaction vessel,

order of addition of reactants, or the amount of waterused in the reaction. 7 Having thus described my invention, what claim and desire to protect by Letters Patentis: [1. A method which comprises reacting at an elevated temperature az-amino alkyl sulphuric acid with a preformed alkali alkylxanthogenate in the presence of alkali molecularly equivalent to the amount of the xanthogenate in a homo m the solution and recovering crystals of a2- geneous liquid medium in which the reactants are soluble, and cooling the reaction mix to recover crystals of a Z-mercapto-thiazoline.

2. A method'which comprises reacting at an elevated temperature a fig-amino alkyl sulphuric acid with a preformed alkali alkyl xanthogenate in the presence of alkali molecularly'equivalent to the amountflof the xanthogenatein a'ho ogeneous liquid medium in which the reactant are soluble, and thereafter cooling and acidif ercapto-thiazoline.

3. A method which comprises reacting at an elevated temperature Z-amino ethyl sulphuric acid with an alkali methyl xanthogenate in the presence of alkali molecularly equivalent to the amount of the xanthogenate in a homogeneous liquid medium in which the reactants are soluble,

amino ethyl sulfuric acid dissolved in 25 gramsof water containing 4 grams of sodium hydroxide. The reaction mixture is heated on a steam-bath 1 and thereafter cooling andacidifying the solution and recovering crystals of 2-mercapto-thiazoline.

SEAPHES'D. SHINKLE.

E T OFFICE 1 

